One thing I would say though - the returning hand in shuto as I understand it is to grab the arm and pin it, not just move it out the way. When we practise it, we normally think hard about the pull back with lots of hip to unbalance the opponent. You could get a little extra if you pull firmly at the elbow with the return hand, just as you have your left hand positioned at 1:15 - grip and pull back hard as you deliver the strike so that he can't straighten his arm to escape your strike.